1. Field of the Invention
The present invention relates to an image scanning device with dual scanning modes, and more particularly to an image scanning device including a rotatable reflection mirror arranged in an optical scanning module of the image scanning device for selectively scanning a reflective original document or a transparent original document.
2. Description of the Prior Art
Typical image scanners are commonly categorized into reflective and transparent types. Reflective type scanner is employed for scanning of reflective document, while transparent type scanner is employed for scanning of transparent document.
Referring to FIGS. 1 and 2, a typical reflective type scanner is shown. The scanner 1 generally includes a top frame 11 with a document positioning plate 12 which is a plane surface made of for example glass or other light transmittable, substantially rigid material, for supporting a reflective original document 10 to be scanned, defining a document scanning window. A cover 13 is pivotally attached to the top frame 11 of the scanner 1 for covering the document positioning plate 12 during the scanning process.
The reflective type scanner 1 generally includes an optical scanning module 14 and a pair of guiding rails 15a, 15b. The optical scanning module 14 is provided with a light source 16, a plurality of light reflection mirrors 171, 172, 173, 174, a focusing lens 18, and an image sensing module 19 such as a Charge Coupling Device (CCD) or a Contact Image Scanning (CIS). The optical scanning module 14 may be moved by a driving device (not shown) along the guiding rails 15a, 15b in a direction I. When the optical scanning module 14 completes a scanning process, the image of the reflective original document 10 is scanned.
As shown in FIGS. 3 and 4, a typical transparent type scanner 2 is shown. The scanner 2 also includes a top frame 21 and a document positioning plate 22. A back lighting module 23 is pivotally attached to the top frame 21 of the scanner 2. The back lighting module 23 is provided with a back light source 26 therein.
The transparent type scanner 2 includes an optical scanning module, 24 moveably supported by a pair of guiding rails 25a, 25b. The optical scanning module 24 includes a plurality of reflection mirrors 271, 272, 273, a focusing lens 28, and an image sensing module 29. The optical scanning module 24 may be moved by a driving device (not shown) along the guiding rails 25a, 25b in the direction I. When the optical scanning module 24 completes a scanning process and with the light provided by the back light source 26, the image of the transparent original document 20 supported on the document positioning plate 22 is scanned.
The conventional reflective or transparent scanner described above can only conduct a specific scanning mode, i.e. the reflective type scanner can not conduct a transparent scanning process, while the transparent type scanner can not conduct a reflective scanning process. In prior art, there is provided with a mode-selective scanner which is capable of selectively conducting reflective or transparent scanning processes. However, the scanner is too complicated to economically manufacture. In addition, it is too complicate to assemble.
Thus, it is desirable to provide an image scanning device with a switching mechanism which is capable of overcoming the problems described above and facilitating scanning operation.
Consequently, a primary object of the present invention is to provide an image scanning device with a rotatable reflection mirror mounted in the optical scanning module. By means of the rotatable reflection mirror, the scanner is capable of conducting either a reflective scanning mode or a transparent scanning mode.
In order to achieve the object set forth, a scanner for selectively scanning reflective and transparent original document in accordance with the present invention comprises an optical scanning module provided with a rotatable reflection mirror for selectively scanning a reflective original document or a transparent original document. The rotatable reflection mirror may be rotated by a driving device comprising such as a stepping motor and a mechanical shaft coupled to the rotatable reflection mirror. At scanning a reflective document, the rotatable reflection mirror is rotated to a first reflection position. A light beam from a first light source projects to the reflective document. The image of the reflective document is reflected by the rotatable reflection mirror and a number of fixed reflective optical path mirrors, and then received by an image sensing module through a first focusing lens. At scanning a transparent document, the rotatable reflection mirror is rotated to a second reflection position. A light beam from a second light source projects to the transparent document. The image of the transparent document is reflected by the rotatable reflection mirror and a number of fixed transparent optical path mirrors, and then received by the image sensing module through a second focusing lens.
Preferably, two position detecting unites are arranged within an effective rotation radius of the rotatable reflection mirror for detecting the position of the rotatable reflection mirror.
To further understand the present invention, reference is made to the following detailed description of a preferred embodiment of the present invention, as well as the attached drawings, wherein: